A causal relationship between chromosomal rearrangements and the genesis of salivary gland pleomorphic adenomas

Summary The results of chromosome analyses performed on 50 pleomorphic salivary gland adenomas in Germany are summarized herein and compared with those obtained on 100 adenomas studied in Sweden. In both series, characteristic or even specific structural chromosomal rearrangements involving either chromosome 8 or 12 were found that allowed the cytogeneticist to distinguish between subgroups. However, the significantly higher percentage of tumors with chromosome abnormalities in the adenomas examined in Germany is particularly noteworthy. In the near future, cytogenetic investigations together with molecular methods will allow investigators to describe basic mechanisms for the development of pleomorphic adenomas in terms of oncogenetics.     

Giant pleomorphic adenomas of the parotid gland

The authors describe four cases of giant pleomorphic adenomas of the parotid gland with the diameter greater then 15 cm in patients treated in the ENT Department, Medical University of Gdańsk in years 1989-2002. Three of the patients were treated surgically--parotidectomy was performed, in first case removing tumor of 28 cm in diameter and 3.2 kg, in second case 15 cm and 0.7 kg and in third case 18 cm and 1.3 kg. The forth patient was disqualified from the surgical treatment because of the metastases to the lungs from the giant malignant pleomorphic adenoma involving half of the head. The authors presented opinions on the diagnostic and therapeutic methods in that disease and also present case reports from Poland and other countries.     

Recurrent pleomorphic adenomas of the parotid gland

In this retrospective study of 19 cases of recurrent pleomorphic adenoma of the parotid gland, all 19 patients underwent primary surgery elsewhere, namely, lumpectomy in five cases and superficial parotidectomy in 14 cases. The age at which those patients with recurrence had originally been seen was significantly earlier than those seen in our series of cases of primary surgery for pleomorphic adenoma. If the primary operation had been a parotidectomy, the average time interval between the first and second operation was 7.7 years; however, if it had been a lumpectomy, it was ten months. Implantability of the tumor and inadequate surgery were reasons for tumor recurrence. The suggested treatment of recurrence is total parotidectomy with preservation of the facial nerve. Revision surgery has been successful in all cases with no further recurrences, except in two cases in which multiple operations had already been performed.     

Multiple primary pleomorphic adenomas of the unilateral parotid gland

BACKGROUND: Classical lateral parotidectomy is the standard surgical procedure for the management of lateral lobe parotid pleomorphic adenomas in most clinical centres. Extracapsular dissection and subtotal lateral parotidectomy are alternatively discussed in current literature and preferred by many authors. CASE: We report on a 20-year-old patient with multiple primary pleomorphic adenomas in the unilateral parotid gland, which preoperatively presented as a solitary tumour node. CONCLUSION: Considering this case we focus on the distinctive surgical procedures for the management of parotid pleomorphic adenomas. We work out, why lateral or even total parotidectomy are justified in the treatment of solitary palpable tumours and why we account lateral parotidectomy as the standard surgical procedure for the management of lateral lobe parotid pleomorphic adenomas.     

A cytochemical study on the salivary gland pleomorphic adenoma (mixed tumor) and the fetal and adult salivary gland

Summary We studied the pleomorphic adenoma of the salivary gland ultrastructurally and cytochemically [Mg²⁺-activated adenosine triphosphatase (Mg²⁺-ATPase)], compared it with normal human fetal and adult salivary glands, and evaluated the histogenesis of this tumor. In the adult salivary gland, reaction products showing Mg²⁺-ATPase activity were localized in the plasma membranes of myoepithelial cells adjacent to the acinar cells or intercalated duct cells. However, in the salivary gland of the 16-week fetus, they were seen along all adjoining plasma membranes of the cells of terminal buds and duct-like structures. The present case of pleomorphic adenoma comprised two histological components: solid and myxomatous areas. Reaction products were seen along adjoining plasma membranes of both light and dark cells in solid areas.     

A cytochemical study on the salivary gland pleomorphic adenoma (mixed tumor) and the fetal and adult salivary gland

We studied the pleomorphic adenoma of the salivary gland ultrastructurally and cytochemically [Mg2+-activated adenosine triphosphatase (Mg2+-ATPase)], compared it with normal human fetal and adult salivary glands, and evaluated the histogenesis of this tumor. In the adult salivary gland, reaction products shows Mg2+-ATPase activity were localized in the plasma membranes of myoepithelial cells adjacent to the acinar cells or intercalated duct cells. However, in the salivary gland of the 16-week fetus, they were seen along all adjoining plasma membranes of the cells of terminal buds and duct-like structures. The present case of pleomorphic adenoma comprised two histological components: solid and myxomatous areas. Reaction products were seen along adjoining plasma membranes of both light and dark cells in solid areas.     

Satellite tumors surrounding primary pleomorphic adenomas of the parotid gland

The occasional local recurrence of benign pleomorphic adenoma (PA) has generally been attributed to the vulnerability of the tumor capsule. Although some reports have also noted the presence of satellite tumors associated with PA recurrence, only few reports have focused on this issue. We paid special attention to the satellite lesions apart from the main tumors and discussed their frequency, origin, nature and the ways of treating them. A total of 108 specimens of primary parotid gland PA resected at the Okayama Saiseikai General Hospital from 1988 to 2008 were microscopically reviewed. Four (3.7%) patients displayed a main mass with satellite tumors in a single parotid gland. The immunohistochemical analysis of p53 and Ki-67 index showed no distinct difference between PAs with satellite tumors and those without. Satellite tumors surrounding the main mass of parotid PA is relatively rare. In most cases, such satellite tumors will arise from capsular perforation of the primary tumor cells. Preoperative evaluation to recognize the existence of satellite tumors would be important and capsular dissection should be discouraged. We could not find any evidence suggesting that primary PA with satellite tumors could be more biologically aggressive than those without.     

颈部罕见巨大涎腺多形性腺瘤1例

涎腺多形性腺瘤（pleomorphic adenoma）又称涎腺混合瘤（mixedtumor）,是最常见的涎腺上皮肿瘤,其中80％～90％发生于腮腺,其次为下颌下腺和舌下腺。虽然绝大多数为良性,但仍有恶变倾向,其恶变率为2％～9％啦’。可发生于任何年龄段,以30～50岁最多见,女性多于男性。现报告1例巨大涎腺多形性腺瘤如下。     

Clinico-pathological findings of recurrent pleomorphic adenomas of the parotid gland]

We analyzed the clinical courses and pathological findings of six recurrent benign pleomorphic adenomas of the parotid gland, compared with fifty-nine primary pleomorphic tumors. Primary cases were treated with extirpation of a tumor nodule with a surrounding area of parotid tissue with preservation of the facial nerve. Of the 59 patients, 42 who had follow-up information have had no recurrent tumors during a average 6.6 years follow up period. On the other hand, all six recurrent cases had received surgical enucleation or excisions elsewhere. To avoid the recurrence of the primary pleomorphic adenoma it was considered to be very important to remove a tumor completely without damaging the tumor capsule. CT scan is very useful to know the relationship between the recurrent tumor and the surrounding important organs. In order to determine the surgical approach and procedures for those cases, it is important to obtain the information of the previous pathological diagnosis or surgical procedures. For the recurrent tumor, complete extirpation of the tumor and surrounding operative scar was necessary for the management of the tumor. When the tumor was tightly adhesive with the facial nerve, sacrifice of the nerve and immediate nerve transplantation might be required.     

Unusual chordoma of the neck region simulating salivary gland pleomorphic adenoma

We report a 34-year-old woman with a cervical chordoma consisting of an intraspinal and extraspinal portion. The extraspinal component of the tumor invaded the deeper structures of the left side of the neck, and was subjected to repeated partial removal. It was misinterpreted as pleomorphic adenoma of salivary gland origin, whereas the intraspinal portion was a neurilemmoma with unusual mucous degeneration.     

Simultaneous primary pleomorphic adenoma in parotid gland and minor salivary gland in the parapharyngeal space

The majority of salivary gland tumours present as a single mass in one gland. Sometimes multiple primary neoplasms can be seen in more than one salivary gland. The most common tumour is Warthin's tumour. Multiple primary pleomorphic adenomas are extremely rare. Most of them are in the major salivary glands. The author reports the first case of simultaneous pleomorphic adenomas in the parotid gland and minor salivary gland at the parapharyngeal space.     

Carcinoma ex pleomorphic adenoma of the salivary gland: an immunohistochemical study

The proliferative activity of the tumor cells and the expression of tumor-associated genes and sex steroid hormone receptors were investigated immunohistochemically in ten cases of carcinoma ex pleomorphic adenoma (Ca-ex-PA) of the salivary glands. These were analyzed in benign and malignant components separately, and then were compared with ten cases of the other malignant tumors [adenocarcinomas, not otherwise specified (ACN) and salivary duct carcinomas (SDC)] and ten cases of pleomorphic adenomas (PA). The results obtained in this study were as follows: (1) malignant component of Ca-ex-PA showed a higher incidence of PCNA and Ki67 than benign component of Ca-ex-PA. A significant difference between benign component of Ca-ex-PA and PA was not observed. (2) A significant difference in the incidence of p53, c-erbB-2, EGFR overexpression was observed only between malignant component of Ca-ex-PA and benign component of Ca-ex-PA. (3) The incidence of PCNA, Ki67, p53, c-erbB-2 overexpression in malignant component of Ca-ex-PA showed the highest data among the four groups. These results suggest that Ca-ex-PA acquired the particular biological behavior in contrast to the other salivary neoplasms in the long-standing process while PA undergoes malignant transformation.     

Clear cell carcinoma arising in pleomorphic adenoma of the minor salivary gland

Malignant change arising in pleomorphic adenoma of the salivary glands is uncommon, with a reported incidence of 2-10 per cent. Only one case where a pleomorphic adenoma became a clear cell carcinoma appears to have been published in the English literature. An additional case of clear cell carcinoma arising in pleomorphic adenoma of a minor salivary gland is reported and the relevant literature discussed.     

The relationship between nuclear DNA content in salivary gland tumors and prognosis

Summary Differences in prognosis between salivary gland mucoepidermoid tumors and acinic cell tumors were compared by means of conventional histopathological grading and nuclear DNA content which was assessed cytochemically by a scanning cytophotometric procedure. The mucoepidermoid tumors were found to show a stronger correlation between histopathological grading and prognosis than did the acinic cell tumors. By using DNA quantification, valuable additional information could be obtained for predicting the behavior of the mucoepidermoid tumors, whereas there was no correlation between DNA content and prognosis for the acinic cell tumors. Regarding the relatively benign clinical course of most mucoepidermoid tumors, the term tumor — as proposed by the World Health Organization's classification — seems appropriate. In contrast, the more severe clinical courses of the acinic cell tumors justify the use of the term carcinoma instead.Presented at the First European Congress of Oto-Rhino-Laryngology and Cervico-Facial Surgery, Paris, 26–29 September 1988Dedicated to Jean Papa Chick of Meru, France, with affection     

Malignant myoepithelioma arising from recurrent pleomorphic adenoma of minor salivary gland.

Malignant myoepitheliomas of the salivary gland are very rare tumors which may either arise de novo or develop in a pre-existing pleomorphic adenoma. We report a case of malignant myoepithelioma of the minor salivary gland that progressed from benign pleomorphic adenoma. The original pleomorphic adenoma was resected in 1979 (the '79 tumor). The first recurrent tumor was operated in 1995 (the '95 tumor). The '95 tumor was diagnosed as pleomorphic adenoma. Although the myoepithelial tumor component was more prevalent in the '95 tumor, histological features of the first recurrent tumor were similar to the '79 tumor. The second recurrent tumor showed more aggressive clinical features (the '98 tumor). It also showed massive growth of myoepithelial tumor cells with bone invasion, which led to the diagnosis of the '98 tumor as malignant myoepithelioma. With adequate surgical margin, the patient has been free from tumor recurrence for 20 months.     

Pleomorphic salivary gland adenomas of the parapharyngeal space. Review of nine cases

Nine cases of pleomorphic salivary gland adenomas of the parapharyngeal space are reviewed. In the discussion which follows we show that five of these tumours were situated medial to the superior constrictor muscle and arose within pharyngeal mucosa. We also outline our views on the management of pleomorphic salivary gland adenoma of the parapharyngeal space with particular reference to biopsy, surgical excision and post-operative radiotherapy.     

A causal relationship between hearing loss and cognitive impairment

Conclusion Moderate hearing loss in young mice caused decreases in cognition associated with spatial working and recognition memories in 6 months. These results provide evidence for a causal relationship between hearing loss and cognitive impairment. Objectives Hypothesized mechanisms to connect sensory and cognitive functions include the sensory-deprivation, information-degradation, and common-cause hypotheses. This study intended to investigate the effect of hearing loss on cognitive function, as estimated by radial arm maze (RAM) and novel object recognition (NOR) tasks in mice through age- and hearing-matched longitudinal work during a 6-month period. Methods Twenty-four male C57BL/6 mice aged 1 month with normal ABR thresholds were used. Twelve mice in the hearing loss (HL) group were exposed to white noise at 110?dB SPL for 60?min every day for 20 days. At post-noise 6 months, all mice underwent RAM and one-trial NOR test. RAM performance measures and NOR discrimination index were compared between two groups. Results At 6 months after noise exposure, all mice in the experimental group had moderate hearing loss. Most of the RAM performances improved gradually within each group across five trials, probably due to learning effect. The HL group showed lower performance scores than the control group in several trial points in the RAM task. The contact time with the novel object was shorter in the HL group than in the control group.